The work, led by plant physiologist Tasios Melis, is so far unpublished. But if it proves correct, it would mean a major breakthrough in using algae as an industrial factory, not only for hydrogen, but for a wide range of products, from biodiesel to cosmetics.
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Melis got involved in this research when he and Michael Seibert, a scientist at the National Renewable Energy Laboratory in Golden, Colorado, figured out how to get hydrogen out of green algae by restricting sulfur from their diet. The plant cells flicked a long-dormant genetic switch to produce hydrogen instead of carbon dioxide. But the quantities of hydrogen they produced were nowhere near enough to scale up the process commercially and profitably.

“When we discovered the sulfur switch, we increased hydrogen production by a factor of 100,000,” says Seibert. “But to make it a commercial technology, we still had to increase the efficiency of the process by another factor of 100.